Excessive sleepiness that interferes with daytime functioning is a common complaint in the elderly. The case-control study of excessive sleepiness in the elderly, that we have been conducting, shows that sleep apnea is an important risk factor for excessive sleepiness. In sleep apnea syndrome there are repeated breathing episodes, i.e., pauses or decrements, during sleep that interrupt sleep and lead to daytime sleepiness. Specifically, we find that individuals with more than 15 such episodes per hour have a statistically significant increased risk of sleepiness, and this risk increases with more such episodes per hour. Our study suggests that about 6 percent of the elderly might therefore benefit from treatment for sleep apnea syndrome. While there are treatments with known efficacy that have been used, and studied, in middle-aged populations, we know nothing about how well such treatments might work in the elderly. This is primarily because elderly with excessive sleepiness seek clinical evaluation for this symptom less frequently. Thus, studies of sleep apnea in the elderly cannot be based on clinic populations. The major current treatment for sleep apnea is use of pressurized air applied through the nose to maintain the airway open (continuous positive airway pressure, CPAP). There are problems with adherence to this cumbersome therapy but we know nothing about adherence in the elderly. We, therefore, propose an intervention study in which we compare, in elderly individuals with sleepiness and documented sleep apnea, the effects of treatment with CPAP and no therapy. Subjects will be randomly assigned into these treatment arms. Since elderly subjects with sleepiness do not commonly seek help at clinical facilities, we will employ a community-based recruitment strategy using lists of individuals in Medicare in geographic regions close to our Sleep Center. This will provide us with the opportunity to determine the efficacy of the case finding strategy that we propose. Particular attention will be paid to recruitment of minority populations, specifically African- Americans. The goals of this study will therefore be the following: evaluating our ability to identify and recruit from the community elderly subjects with problems with sleepiness who have sleep apnea syndrome; evaluating the effect of treatment of sleep apnea on activity of daily living and other outcomes; and determining the patterns of use of CPAP in comparison to published data in middle-aged subjects. These data will give novel definitive information both about identification and treatment of sleep apnea in the elderly.